Colloidal Titration of Aqueous Zirconium Solutions with Poly(vinyl sulfate) by Potentiometric Endpoint Detection Using a Toluidine Blue Selective Electrode

Abstract

Zirconium oxy-salts were hydrolyzed to form positively charged polymer or cluster species in acidic solutions. The zirconium hydrolyzed polymer was found to react with a negatively charged polyelectrolyte, such as poly(vinyl sulfate), and to form a stoichiometric polyion complex. Thus, colloidal titration with poly(vinyl sulfate) was applied to measure the zirconium concentration in an acidic solution by using a Toluidine Blue selective plasticized poly(vinyl chloride) membrane electrode as a potentiometric end-point detecting device. The determination could be performed with 1% of the relative standard deviation. The colloidal titration stoichiometry at pH ≤ 2 was one mol of zirconium per equivalent mol of poly(vinyl sulfate).